Honing tool with guide means to prevent tool wear

ABSTRACT

An internal honing tool. The honing tool includes a tool body which has an outer periphery and a plurality of circumferentially spaced recesses therein. The recesses include first and second portions and extend through the outer periphery of the tool body. Abrasive members are mounted in the first portions of each of the recesses and extend outwardly beyond the outer periphery of the tool body for honing a work piece. Guide members are mounted in the second portions of the recesses and act to guide the abrasive members for radial movement relative to the tool body. These guide members undergo thrust wear, torque wear, and outside diameter wear so as to avoid wearing of the tool body. Securing members removably secure the guides and abrasive stones to the tool body. The structure avoids wear of the tool body while only the abrasive members and guide members require replacement.

United States Patent 1 1 McDonald [451 Jan. 21, 1975 HONING TOOL WITH GUIDE MEANS TO PREVENT TOOL WEAR [75] Inventor: Clarence A. McDonald, Richmond,

Ind.

[73] Assignee: National Automatic Tool Company,

Richmond, Ind.

[22] Filed: Feb. 5, 1973 [21] Appl. No.: 329,855

[52] US. Cl 51/331, 51/344, 51/346 [51] Int. Cl B24b 33/08 [58] Field of Search 51/331, 338-354 [56] References Cited UNITED STATES PATENTS 2,000,611 5/1935 Prange 51/331 X 2,330,184 9/1943 Hause 51/346 2,350,969 6/1944 Sunnen 5l/338 X 2,694,885 11/1954 Peden 51/331 Primary Examiner-Al Lawrence Smith Assistant Examiner-Nicholas P. Godici Attorney, Agent, or FirmMolinare, Allegretti, Newitt & Witcoff [57] ABSTRACT An internal honing tool. The honing tool includes a tool body which has an outer periphery and a plurality of circumferentially spaced recesses therein. The recesses include first and second portions and extend through the outer periphery of the tool body. Abrasive members are mounted in the first portions of each of the recesses and extend outwardly beyond the outer periphery of the tool body for honing a work piece,

Guide members are mounted in the second portions of the recesses and act to guide the abrasive members for radial movement relative to the tool body. These guide members undergo thrust wear, torque wear, and outside diameter wear so as to avoid wearing of the tool body, Securing members removably secure the guides and abrasive stones to the tool body. The structure avoids wear of the tool body while only the abrasive members and guide members require replacement.

10 Claims, 8 Drawing Figures PATENTED m2] ms SHEEI 10F 2 PATENTED I975 3.861 .091

SHEET 2 OF 2 HONING TOOL WITH GUIDE MEANS TO PREVENT TOOL WEAR BACKGROUND OF THE INVENTION FIELD OF THE INVENTION and DESCRIPTION OF THE PRIOR ART This invention relates to an improved honing tool and it particularly relates to a honing tool which simplifies the mounting and replacement of the abrasive members used in the tool while, at the same time, extending the life of the tool body in which the abrasive members are mounted.

Honing machines are precision tools used wherever it is necessary to have a particularly precision finished surface. One such example of where such honing tools are used extensively is the internal honing of the cylinders of automotive and aircraft engine cylinder blocks. It is well known that the manufacturing of cylinder blocks, particularly for automotive engines, is a highly automated operation. In any highly automated operation, it is always important to reduce the amount of maintenance and down time for any particular machine.

Directly related to the amount of down time for a machine is the frequency of replacement of worn tool parts. In honing tools, which are commonly used in the honing of automotive engine blocks, it is common for the tool body itself to become worn from the abrasive element because the abrasive is normally mounted directly onto the tool body. Basically, there are three types of wear which occur on the tool body during the honing operation. First there is a certain amount of outside diameter (O.D.) wearing of the tool body as a result of the rotary and reciprocal motion of the honing tool during the honing operation within the cylinder. Secondly, thrust wear develops on the tool body as a result of the reciprocal motion of the tool body within the cylinder. The third type of wearing is torque wear. Slots or flanges are machined on the tool body and these slots or flanges cooperate with slots or flanges on the abrasive member to guide the abrasive member, during the honing operation, in the radial movement of the abrasive relative to the tool body during the honing operation. The torque wear results from the torquing of the abrasive element or stone within the tool body, resulting in wearing of the tool body along the portion of the tool body which receives the abrasive elements.

From the foregoing, it is clear that the tool body, as well as the abrasive members or stones become worn out. The replacement of the honing members or stones is normal and expected. The replacement of the entire tool body itself, however, is not only expensive, but it is also more time consuming than the mere replacement of the stones. Therefore, any way in which the life of the tool body can be extended would be highly advantageous, particularly in automated operations.

In addition to the above, there are other significant disadvantages of conventional methods for mounting the abrasive stones in the honing tool body. One such disadvantage is that, in some structures, the abrasive member is normally secured to the tool body by screws or bolts which pass through the outer or working face of the abrasive or abrasive holder. This structure requires counterbored holes in the outer peripheral portion of the abrasive tool. The counterbored holes lead to a picking up of the metal removed during the honing operation, which pick up may have an adverse effect on the honing operation. Furthermore, another problem is encountered, in some structures, when the abrasive assembly strikes an obstruction in the bore of the workpiece because the screws used to hold the guide can then become sheared off in the tool body. The removal of sheared screws within the body is a rather difficult and time consuming task, which is particularly undesirable with automated equipment. Such is the case in Hause US. Pat. No. 2,330,184 wherein a guard strip shown therein is threaded into the tool body.

SUMMARY OF THE INVENTION It is therefore an important object of this invention to provide an improved internal honing tool wherein tool body wear problems and abrasive replacement problems encountered in similar prior art devices are significantly reduced.

It is also an object of this invention to provide an improved honing tool which incorporates the three major wear points normally encountered in honing operations into a single replaceable insert or guide which is used to secure the abrasive member to the tool body while at the same time the insert absorbs the wear normally encountered by the tool body so as to extend the life of the tool body.

It is a further object of this invention to provide an improved internal honing tool, wherein a separate insert or guide is used in conjunction with each of the abrasive members for the purpose of undertaking the thrust wear, the torque wear, and the OD. wear normally undertaken by the tool body itself.

It is yet a further object of this invention to provide an improved internal honing tool wherein a combination guide and wear insert is provided so as to simplify the replacement of the abrasive members or stones and at the same time extend the life of the tool body.

It is yet another object of the invention to provide an improved internal honing tool wherein the mounting of the abrasive to the tool body substantially avoids the problem of pick up of the metal being removed during the honing operation, and wherein the problem of shearing or breaking of the screws in the tool body itself is substantially avoided.

It is still a further object to provide a honing tool body which is particularly characterized by its simplicity of construction.

Further purposes and objects of this invention will appear as the specification proceeds.

The foregoing objects are accomplished by my improved internal honing tool which includes a tool body which has an outer periphery having a plurality of spaced recesses in the tool body. The recesses each include first and second portions and the recesses extend through the outer periphery of the tool body. Stones or abrasive members are mounted in each of the first portions of the recesses and extend outwardly just beyond the outer periphery of the tool body so as to accomplish the honing of a workpiece, such as a cylinder of an automotive machine. Inserts are mounted in the second portions of the recesses and serve a dual function of guiding the abrasive means during the honing operation and these inserts also undergo the thrust wear, the torque wear and the outside diameter wear, which wear positions normally occur on the tool body. Screws are provided for removably securing each set of the abrasive members and inserts in each set of recesses of the tool body. The screws are accessible from the portions of the tool body between the recesses and the screws do not pass-through the outer periphery of either the abrasive member or the guide or insert.

BRIEF DESCRIPTION OF THE DRAWINGS A particular embodiment of the present invention is illustrated in the accompanying drawings wherein:

FIG. 1 is a partially broken, partially sectioned, side view of a honing tool which uses my invention;

FIG. 2 is an end view of the embodiment of FIG. 1;

FIG. 3 is a pictorial view of the combination guide and wear insert used for mounting the abrasive members to the tool body shown in FIGS. 1 and 2;

FIG. 4 is a pictorial view of the abrasive member which includes an abrasive portion and a holder portion, which abrasive member is used in the embodiment illustrated in FIGS. 1 and 2;

FIG. 5 is a broken end view, similar to FIG. 2, wherein an alternate guide and wear insert is illustrated;

FIG. 6 is a pictorial view of the alternate insert illustrated in FIG. 5;

FIG. 7 is a broken end view, similar to FIG. 5, wherein another alternate guide and wear insert is shown; and

FIG. 8 is a pictorial view of the alternate insert illustrated in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, there is shown the lower portion of a honing tool, generally 10, which includes a substantially cylindrical tool body 12, which has a hollow interior. A hollow cylindrical drive shaft 14 is mounted in the interior of the tool body 12. The drive shaft 14 includes a lower stepped portion 16, which is within an internal flange 18 within the tool body 12. The lower end of the drive shaft 14 is threaded and a nut 20 is threadably secured thereto for securing the drive shaft 14 in place within the tool body 12 by bearing against the lower or outer surface portion of the flange 18. The drive shaft 14 has a push rod 22 passing downwardly through its hollow interior. The push rod 22, in a conventional manner, is reciprocalv within the tool body 12 and within the drive shaft 14. Such motion ultimately moves the abrasive members or stones 24 laterally outwardly to the desired honing diameter for the internal honing operation.

The push rod 22 is rigidly interconnected to a cone assembly 26 by means of a drive pin 28. The cone assembly 26 includes an upper or inner cone portion 30 and a lower or outer cone portion 32. A plurality of longitudinally or axially elongated slots 34 are located in the outer and lower enlarged wall 33 of the tool body 12. As shown in FIGS. 1 and 2, a plurality of expanding plates 36 are slidably mounted within the slots 34 for lateral movement within the tool body 12. Each expanding plate 36, as best shown in FIG. 1, includes a tapered upper or inner portion 38 and a tapered lower or outer portion 40. As seen in FIG. 1, the tapered upper portions 38 slidably engage the exterior surface of the upper cone 30 while the tapered lower portions 40 slidably engage the exterior surface of the lower cone 32. In a conventional manner, when the push rod 22, is pushed outwardly or downwardly, the cones 30 and 32 are also moved outwardly or downwardly. With this downward movement, the expanding plates 36 slide on their tapered portions 38 and 40 along the exterior surfaces of the cones 30 and 32. This moves all plates 36 laterally outwardly. The stones are urged against the outer edges of the plates 36 by the spring members 56, and the stones 24 are moved to the desired outer diameter for the honing operation by the lateral movement of the plates 36.

Referring to FIG. 2, the tool body 12 includes a plurality of recesses 42, each of which include a stone receiving portion 44 and an insert receiving portion 46. The stone members 24 are singly, but slidably received within the stone portions 44 while the insert members 48 are rigidly mounted within the insert portions 46 of the recesses 44.

The stone members 24 each include an abrasive portion 50 and a non-abrasive holder portion 52, as best seen in FIG. 4. Generally, the holder portion 52 is constructed of a non-abrasive plastic material and the abrasive portion 50 is bonded to the holder portion 52 in any suitable manner. As is seen in FIG. 4, the holder portion 52 includes upper and lower hook sections 54. As seen in FIGS. 1 and 2, the hook sections 54 each receive generally circumferential spring members 56 which normally urge all of the stones 24 to the full in position. Thus, when the push rod 22 is raised to its uppermost or innermost position, the springs 56 urge the stones 24 inwardly to the full in position. This is done, for example, during insertion and withdrawal of the honing tool in and out of the cylinder of an automotive engine block.

The most important feature of the inventive structure 10 is the provision of the insert member 48. The insert member 48 isreceived within the insert portion 46. The insert member 48 is constructed of a rigid material, and is dimensioned to be received within the insert receiving portions 46 of the recesses 42 in close dimensional relationship to the walls thereof. The members 48 of the embodiment of FIGS. 1 3 are desirably constructed of a metal as steel or bronze. The insert members 48 slidably receive the stone members 24 including the holder portions 52 thereof within the recesses 42. Desirably, the insert members 48 include grooves or slots 58 which are radial respective to the tool body and to the desired direction of movement of the stone members 24 within the tool body 12 for a honing operation. As seen in FIG. 4, the holder portion 52 of the abrasive assembly 24 includes ridges 60 which are slidably carried within the grooves 58 of the guide inserts 48. Each insert 48 is fixedly secured within the tool body 12 by socket head bolts 62. A dowel pin 64 may, if desired, be positioned intermediate each pair of spaced bolts. The bolts 62 and pins 64 pass into apertures 66, threaded apertures in the case of the bolts 62, in the inserts 48. It will be noted that the bolts 62 are accessible, at their head ends, from solid tool body sections 68 provided between the recesses 42.

Referring to FIGS. 5 and 6, there is shown an alternate guide member 74. The guide member 74 has an enlarged outer flange portion 76 which provides the outer periphery of the member 74 with longer wear surface resulting in a longer life for the guide or insert 74. Also, the tool body 12 has a cut-out portion 78 for receiving the lip or flange portion 76. The member 74 has two tapped holes 80 without an intermediate opening for a pin, as shown in the embodiment of FIGS. 1 4. It is preferred to avoid using an intermediate pin to simplify the installation of the guidemember. The member 74 is preferably made of a metal, such as steel, or, in some applications, the member is preferably constructed of a powdered or sintered metal.

The embodiment of FIGS. 7 and 8 shows a guide or insert member which is constructed of plastic or nylon. The structure of the guide 78 is similar to the guide 74 as it includes an outer flange 84. Also, the tool body has a cut-out portion 86 which receives the flange 84. A significant advantage of the plastic insert member 82 is it enables the securement and removal of the guides to be greatly simplified. A projecting plug 88 is provided on the member 82 and the plug is fixedly received by an aperture 90, in the tool body. With this embodiment, the guide members can all be replaced on the tool body in a fraction of the time required for the embodiments of FIGS. 1 4 and 5 and 6. Therefore, the embodiment 82 is preferably used whenever the honing operation is such as to permit the use of the plastic inserts.

The inserts 48, 74 and 82 incorporate three of the major wear points commonly encountered by a honing tool body. As a result, only the inserts, generally, need to be replaced when worn and it is not necessary to replace the entire tool body. Reciprocal, that is, up and down movement of the honing tool 10 within a cylinder, for example, causes thrust wear which is absorbed along the longitudinal sides of the grooves 58 of the inserts and of the ridges 60 of the holder portions 52 of the stone assemblies 24. Additionally, as a result of rotary motion of the honing tool 10, there is torque wear on the lateral face 70 of the insert and on the face 72 of the holder portion 52 of the abrasive member 24. Finally, the insert extends slightly outwardly beyond the outside diameter of the tool body, as to within five to ten thousandths of an inch of the CD. of the working diameter of the stone member 24. The inserts not only back up the stones 24 during the honing operation, but the outer periphery of the inserts undergo peripheral or outside diameter (O.D.) wear. These three major wear points, that is, O.D. wear, thrust wear, and torque wear, are normally absorbed by the tool body itself. In our invention, however, these wear points are undertaken by the inserts so it is merely necessary to replace the inserts 48. The inserts 48 and stones 24 may be removed and readily replaced by new inserts and stones 24 if needed. The replacement occurs quickly and assembly is relatively inexpensive. Furthermore, in the event that the stones 24 strike an obstruction, for example, and a bolt holding an insert is broken, replacement is simplified, because there is no problem of a sheared bolt remaining within the tool body, such having occurred with prior art honing tool bodies. Furthermore, the manner of securing the inserts to the tool body eliminates the securement of the abrasive element directly through the outer face of the abrasive element, which arrangement causes undesirable pick up of the metal being removed during the honing operation.

While in the foregoing there has been provided a detailed description of particular embodiments of the present invention, it is to be understood that all equivalents obvious to those having skill in the art are to be included within the scope of the invention as claimed.

What I claim and desire to secure Letters Patent is:

1. An internal honing tool comprising, in combination, a tool body having an outer periphery and a plurality of spaced recesses in said tool body, said recesses having first and second portions and extending through said outer periphery, abrasive means mounted in each of said first portions and said recesses and extending outwardly at least slightly beyond said outer periphery for internally honing a work piece, means mounted in each of said second portions of each of said recesses for guiding each of said abrasive means for radial movement during a honing operation, said guiding means and said abrasive means cooperating to define means for undergoing thrust wear, caused by reciprocal motion of said tool, and for undergoing torque wear, caused by rotary motion of said tool, said cooperating means including interengaging portions on said guiding means and on said abrasive means for substantially preventing axial movoment between said guiding means and said abrasive means, and said guiding means also defining means projecting at least slightly beyond said outer periphery for undergoing outside diameter wear, said thrust wear, torque wear and outside diameter wear normally being encountered by said tool body during a honing operation, all of said undergoing means avoiding such wearing on said tool body, and means for removably securing each set of said abrasive means and said guiding means in each of said recesses of said tool body.

2. The article of claim 1 wherein each of said guiding means extends laterally outwardly beyond said outer periphery of said tool body and laterally inward of the outer periphery of said abrasive means when in the operative position.

3. The article of claim 1 wherein said abrasive means includes an abrasive portion and a nonabrasive holder portion, said non-abrasive holder portion including one of said interengaging portions and cooperating with said guiding means.

4. The article of claim 1 wherein said interengaging portions of said cooperating means include means for slidably guiding said abrasive means for radial movement relative to said tool body during a honing operation.

5. The article of claim 4 wherein said abrasive means includes a plastic holder portion which includes ridges, defining one of said interengaging portions, extending in the direction of radial movement of said abrasive means, and said guiding means includes slots, defining the other of said interengaging portions, for slidably receiving said ridges, said slots and said ridges providing said means for undergoing thrust wear.

6. The article of claim 1 wherein said tool body includes unitary rigid sections between said recesses, and said securing means are accessible from said unitary rigid sections.

7. The article of claim 6 wherein said securing means comprises threaded members which pass through said tool body and are threadably received'by said guiding means.

8. The article of claim 1 wherein said guiding means and said tool body include cooperating means for securing said guiding means to said body without the use of additional fasteners.

9. The article of claim 8 wherein said guiding means is constructed of plastic.

10. An internal honing tool comprising, in combination, a tool body having an outer periphery and a plurality of spaced recesses in said tool body, said recesses having first and second portions and extending through said outer periphery, abrasive means mounted in each of said first portions and said recesses and extending outwardly at least slightly beyond said outer periphery for internally honing a work piece, means mounted in each of said second portions of each of said recesses for guiding each of said abrasive means for radial movement during a honing operation, said guiding means including a plastic holder portion which includes ridges or slots extending in the direction of radial movement of said abrasive means, said guiding means including slots or ridges for slidably receiving said ridges or slots, said guiding means and said abrasive means cooperating to define means for undergoing thrust wear, caused by reciprocal motion of said tool, and for undergoing torque wear caused by rotary motion of said tool, said slots and said ridges providing said means for undergoing thrust wear, and said guiding means also defining means projecting at least slightly beyond said outer periphery for undergoing outside diameter wear, said thrust wear, torque wear and outside diameter wear normally being encountered by said tool body during a honing operation, all of said undergoing means avoiding such wearing on said tool body, and means for removably securing each set of said abrasive means and said guiding means in each of said recesses of said tool body. 

1. An internal honing tool comprising, in combination, a tool body having an outer periphery and a plurality of spaced recesses in said tool body, said recesses having first and second portions and extending through said outer periphery, abrasive means mounted in each of said first portions and said recesses and extending outwardly at least slightly beyond said outer periphery for internally honing a work piece, means mounted in each of said second portions of each of said recesses for guiding each of said abrasive means for radial movement during a honing operation, said guiding means and said abrasive means cooperating to define means for undergoing thrust wear, caused by reciprocal motion of said tool, and for undergoing torque wear, caused by rotary motion of said tool, said cooperating means including interengaging portions on said guiding means and on said abrasive means for substantially preventing axial movement between said guiding means and said abrasive means, and said guiding means also defining means projecting at least slightly beyond said outer periphery for undergoing outside diameter wear, said thrust wear, torque wear and outside diameter wear normally being encountered by said tool body during a honing operation, all of said undergoing means avoiding such wearing on said tool body, and means for removably securing each set of said abrasive means and said guiding means in each of said recesses of said tool body.
 2. The article of claim 1 wherein each of said guiding means extends laterally outwardly beyond said outer periphery of said tool body and laterally inward of the outer periphery of said abrasive means wHen in the operative position.
 3. The article of claim 1 wherein said abrasive means includes an abrasive portion and a nonabrasive holder portion, said non-abrasive holder portion including one of said interengaging portions and cooperating with said guiding means.
 4. The article of claim 1 wherein said interengaging portions of said cooperating means include means for slidably guiding said abrasive means for radial movement relative to said tool body during a honing operation.
 5. The article of claim 4 wherein said abrasive means includes a plastic holder portion which includes ridges, defining one of said interengaging portions, extending in the direction of radial movement of said abrasive means, and said guiding means includes slots, defining the other of said interengaging portions, for slidably receiving said ridges, said slots and said ridges providing said means for undergoing thrust wear.
 6. The article of claim 1 wherein said tool body includes unitary rigid sections between said recesses, and said securing means are accessible from said unitary rigid sections.
 7. The article of claim 6 wherein said securing means comprises threaded members which pass through said tool body and are threadably received by said guiding means.
 8. The article of claim 1 wherein said guiding means and said tool body include cooperating means for securing said guiding means to said body without the use of additional fasteners.
 9. The article of claim 8 wherein said guiding means is constructed of plastic.
 10. An internal honing tool comprising, in combination, a tool body having an outer periphery and a plurality of spaced recesses in said tool body, said recesses having first and second portions and extending through said outer periphery, abrasive means mounted in each of said first portions and said recesses and extending outwardly at least slightly beyond said outer periphery for internally honing a work piece, means mounted in each of said second portions of each of said recesses for guiding each of said abrasive means for radial movement during a honing operation, said guiding means including a plastic holder portion which includes ridges or slots extending in the direction of radial movement of said abrasive means, said guiding means including slots or ridges for slidably receiving said ridges or slots, said guiding means and said abrasive means cooperating to define means for undergoing thrust wear, caused by reciprocal motion of said tool, and for undergoing torque wear caused by rotary motion of said tool, said slots and said ridges providing said means for undergoing thrust wear, and said guiding means also defining means projecting at least slightly beyond said outer periphery for undergoing outside diameter wear, said thrust wear, torque wear and outside diameter wear normally being encountered by said tool body during a honing operation, all of said undergoing means avoiding such wearing on said tool body, and means for removably securing each set of said abrasive means and said guiding means in each of said recesses of said tool body. 